ぺトラ・ノヴァ・CCUS プロジェクト

－石炭火力発電所排ガスからのCO₂ 回収および老朽化油田の原油増産－

抄録

Carbon Capture, Utilization, and Storage （CCUS）, which is the combination of Carbon Capture from an anthropogenic source, followed by Utilization and Storage through an Enhanced Oil Recovery （EOR） process, is widely recognized as a useful technology to reduce greenhouse gas （GHG） emissions economically.

Petra Nova CCUS is one of such projects located near Houston, TX in the United States. In this project, a CO₂ capture and recovery unit has been constructed adjacent to a power plant in order to capture CO₂ from the flue gas of coal-fired power generating unit. A chemical absorption technique is used for the CO₂ capture process, achieving a CO₂ product purity of 99.9%. CO₂ recovery capacity is approximately 5,000 tons per day and 1.5 million tons per year considering operational uptime. The target field for EOR is a giant onshore legacy oil field, located 130 km from the power plant.

Historical oil production was boosted with infill-drilling and pattern-waterflood operations in 1970ʼs; however, prior to EOR operations, field oil production has declined to around 300 barrels oil per day. The captured CO₂ at the power plant is compressed and transported to this oilfield at under supercritical pressure condition through a 12 inch pipeline, then injected to the target oil reservoir for CO₂-EOR.

The Petra Nova CCUS project was sanctioned in July 2014 and the capture system was completed in December 2016, with first CO₂ capture and injection into the reservoir, and followed by first EOR oil production in February 2017. Stable operations have continued so far, resulting in 2 million tons of CO₂ captured and more than 2 million barrels of oil produced.

This project is quite unique in assigning a value to CO₂. The Petra Nova CCUS project is a good example of collaboration between reducing GHG and increasing oil production, that is, collaboration between environmental protection and the oil business.